Any hard data as to when tires should be replaced?

[Andrew Carey]

One person has more or less suggested tire replacement after 5 years ... anyone have a more definitive or specific recommendation? I have a 99 safari with original tires; I haven't gone on a trip in a couple of years, tread is in good shape, but as the previous post noted tires degrade even without use or wear. Motorcycle safety experts say don't use any tire more than 3 years old. But Les Schwab dealership told me not to worry about it. Anyone with more specific info? abc

[Action]

There are several thoughts that I am aware of. Some revolve around visual inspection. I am not aware of a a hard and fast rule as written by a tire manufacture. (And you can search those sites, it's really EZ)

I am not adovcating my usage, and I have gone way past 5 years. If I were to check tire mfg dates I bet it is double that. So far it's working for me. And I know I better not go on that next trip w/o new tires. All 4.

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[Road Ruler]

You raise a good question.

Soon after getting our 1973 Safari home a few years ago I took one of the P rated Michelins (Sears Branding) to Sears for evaluation. The manager at Sears said that the tire model had not been sold for 13 years and they were at least that old. Makes one wonder how long a tire will last. "???????"

[steelbird312]

Originally Posted by andycarey

One person has more or less suggested tire replacement after 5 years ... anyone have a more definitive or specific recommendation? I have a 99 safari with original tires; I haven't gone on a trip in a couple of years, tread is in good shape, but as the previous post noted tires degrade even without use or wear. Motorcycle safety experts say don't use any tire more than 3 years old. But Les Schwab dealership told me not to worry about it. Anyone with more specific info? abc

Hello Andy,
I have read everything there is to read, 3 times over, and then I find something new. In a nut shell, Goodyear as well as Michelin have quite a bit to say about tires, age, etc. Goodyear says 5 years on age as most trailer tires get used very few times a year, and the rest of the time they are degrading. Why? 2 reasons. UV rays are focused many times, at the same section of tire day after day, after day. Very hard on tires. The other reason is that the polymers used in tires to prolong life require heat and flexing to help them migrate through the rubber. Since they are sedintary so much of the time, the outer portion of the tires degrade from exposure. Of smaller consequence, yet still effecting the situation is the flat spot on the tire, as well as the material the tire is sitting on could hold moisture, oil, etc against that part of tire, or could promote leaching of the same polymers mentioned earlier.
5 years seems to be the safe age. Truck, auto, and other frequently used tires can last much longer as age goes, if the tread holds out.
The dates can be found on the sidewall. Locate the DOT symbol, then go to the last oval after it that contains 3 or 4 numbers. The first two are the week of the year, and the last 1 or 2 incicate the year.
2299 would be 22 week of year 1999.
223 would be the 22 week of 2003
Now, personal experience. I have seen used as well as used myself old tires. But after buying a 1996 Excella that sat unsold in one spot until 1999, and then having a blowout about 2000 miles later, I decided that a long side peice of aluminum costs a WHOLE LOT more than a couple of Goodyear Marathons.
Oh, the very best thing you can do to make your tires last is to keep them inflated properly. Check them everyday before you pull. It costs absolutely nothing.

[klattu]

When they get hard

[Andrew Carey]

Thanks for the replies! I have kept my tires covered and well inflated, but for various reasons the trailer has not been moved much in the last 2 years. The tires look hardly used. Nevertheless, I'm going to go ahead and have them all replaced before an upcoming trip. From what I've read here and on motorcycle threads, there are many changes that can occur in the rubber without obvious surface imperfections; this changes can lead to overheating and to stiffness in the rubber that can lead to failure. Since mine is a 99, the tires are at least 8 years old; I checked the DOT code--468--that makes them going on 9 years old.

[Action]

Andy,

That would make your tires built in week 48 of 1998. Or early December 1998. Kinda used up from most peoples view point.

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[moosetags]

I have some personal experience to share on the tire age problem. I own a 1981 DeLorean Gullwing Coupe that I purchased in 1989 from the original owner with 7000 miles on it. It still had the original Goodyears on it in 1994 with 9000 miles on it and the tires. SuEllyn was driving it on I-295 in Jacksonville when a tire sidewall blew out. Fortuneately, SuEllyn was able to bring the Dlorean to a safe stop on the shoilder. I started researching the tire issue and was told by Goodyear that little-worn tires that are over seven years old are not really safe. I have followed this advice since.